The motion of no-confidence vote in President Jacob Zuma will show whether the former minister and his colleagues will walk the talk.

On Tuesday, August 8, the National Assembly will convene just after 2pm. Speaker Baleka Mbete will offer a moment of prayer or reflection and will proceed to entertain motions without notice, maybe some member's statements, before she will proceed to notices of motion.

At that moment the African National Congress (ANC), weakened by a president who outsourced his responsibilities to the highest bidders, governing a state riddled by corruption and capture and still smarting from losing three more metros to opposition parties, will be confronted with its own mortality. If there are no court reviews of Mbete's expected decision not to allow a secret ballot, she will then introduce the Democratic Alliance's (DA) motion of no confidence for debate and a division (a vote). And the moment of reckoning will arrive.

The ANC's caucus hasn't met since before the party's policy conference two weeks ago, but there's serious chatter that it won't be able to enforce the three-line whip that Jackson Mthembu and his fellow whips are expected to announce before the vote. (A three-line whip: so called because the whippery in the House of Commons used to underline the written order that all MP's need to attend a specific vote three times to show the gravity of the situation.) That means there could be dissent: either in the form of abstentions, stay-aways or votes contrary to the party position.

The feeling in certain sections of the divided caucus -- President Jacob Zuma still enjoys strong support -- is that the party has now reached its tipping point. Not everyone feels the same way and many are still content to sit out the daily revelations about state capture until it peters out and is accepted as reality by a numbed public. But a growing number of ANC MP's are starting to steel themselves for the motion of no confidence and a decision which will define them for the rest of their lives.

It's a complex situation and Pravin Gordhan said as much during an interview on Radio 702 earlier this week, arguing that any decision needs to be taken strategically in order to ensure the desired, eventual outcome. He was supported by Roelf Meyer, the erstwhile National Party government negotiator, who said he considered leaving the party in the 1980's but decided to work for change from within. His decision enabled him to help dismantle apartheid, he said during the same broadcast.

John Steenhuisen, the DA's chief whip, is not convinced there will be any ANC MP who will follow the courage of their conviction and support the motion to dismiss Zuma from office. He argues the most visible form of dissent might be MP's from the South African Communist Party (SACP) abstaining in a bloc. He's also not convinced that Gordhan will actually go the whole hog and support the DA-led motion: "He might, at best abstain, but will most probably just stay away."

The opportunity to be on the right side of history is approaching, and approaching fast.

There's precedent for that: Professor Ben Turok, the veteran ANC activist who helped write the economic clauses in the Freedom Charter, stayed away when the vote on the infamous Protection of State Information Bill took place. But even Turok – fiercely independent and famously crusty – could not bring himself to vote against the party, even if it was for something as repressive and anti-democratic as that bill.

Some ANC MP's, however, say there is a quiet resolve building up in certain quarters of the caucus, a realisation that change is inevitable and that the opportunity to be on the right side of history is approaching, and approaching fast. "We are realising: 'For heaven's sake: things can't go on like this,'" one MP said in confidence. But the reality of threats against Makhosi Khoza, the outspoken ANC MP, have scared some MP's out of supporting her publicly. There's also frustration that Deputy President Cyril Ramaphosa isn't giving strong enough direction to the caucus, many who are ready to support him. And there's a third school of thought that disgruntled and disillusioned MP's should just sit tight: the December elective conference isn't too far off.

It's crystal clear that Gordhan will be the fulcrum around which the Renegades will coalesce. He's made his feelings pretty clear this week, saying Zuma "should step aside, let the country reset and chart the course Nelson Mandela and others set". On Tuesday, at the mass meeting of civil society organisations in Randburg, I asked him if the solidarity of purpose shown by civil society is surprising to him if it excites him. He replied: "Some of us have seen this happen before."

The DA's motion will probably not be carried. It will be the biggest story of the decade if it does. But Gordhan, Derek Hanekom and probably a handful of like-minded MP's, don't have a choice anymore. They are going to have to press the green button: "yea".